A mosaic of six H I line observations with the Australia Telescope Compact Array is used to search for intergalactic gas in the NGC 1808 group of galaxies .
Within the field of view of about 1 \aas@@fstack { \circ } 4 \times 1 \aas@@fstack { \circ } 2 no emission from intergalactic H I gas is detected , either in the form of tidal plumes or tails , intergalactic H I clouds , or as gas associated with tidal dwarf galaxies , with a 5 \sigma limiting sensitivity of about 3 10 ^ { 18 } cm ^ { -2 } ( or 1.4 10 ^ { 7 } M _ { \odot } at a distance of 10.9 Mpc , for the given beam size of 127 \aas@@fstack { \prime \prime } 9 \times 77 \aas@@fstack { \prime \prime } 3 ) .
The H I data of NGC 1792 and NGC 1808 , with a velocity resolution of 6.6 km s ^ { -1 } , confirm the results of earlier VLA observations .
Simultaneous wide-band 1.34 GHz continuum observations also corroborate the results of earlier studies .
However , the continuum flux of NGC 1808 measured by us is almost 20 % higher than reported previously .
No radio continuum emission was detected from the type Ia supernova SN1993af in the north-eastern spiral arm of NGC 1808 .
A comparison of NGC 1792 and NGC 1808 shows that it is not primarily the total energy input that makes the big difference between the starburst-related outflow in NGC 1808 and the absence of such extraplanar features in NGC 1792 , but the area over which the energy released by stellar winds and supernovae is injected into the ISM .